混凝土连续箱梁预应力单端张拉对其产生的影响  

The Impact on Concrete Continuous Box Girder Caused by Prestressed Single-ended Tensioning

作　　者：熊扬 陈卓 XIONG Yang;CHEN Zhuo(Chongqing Transportation Planning Survey and Design Institute,Chongqing 401121)

机构地区：[1]重庆市交通规划勘察设计院

出　　处：《黑龙江交通科技》2019年第10期88-90,92,共4页Communications Science and Technology Heilongjiang

摘　　要：为了研究预应力混凝土连续梁桥在施工过程中预应力张拉由两端张拉改为单端张拉对桥梁受力的影响,以同一宽度不同跨径的预应力混凝土箱梁为分析对象,采用数值计算的方法进行空间杆系有限元的计算分析。分析结果表明:当预应力张拉方式由双端张拉变更为单端张拉后,未张拉端的预应力损失远大于张拉端的损失,且随着跨径的增加而增大,未张拉侧边跨跨中计算弯矩减小,跨中底板处应力减小,因此若张拉方式更改为单端张拉,则需要通过进行计算分析确定具体的影响,确保足够的安全富余。With a view to investigating the force bearing impacts of prestressed concrete continuous girder bridge while the prestressed tensioning changed into single-ended tensioning from both ends during construction,I take the prestressed concrete box girder with same width and different span as analysis object,and adopt the method of numerical computation to compute and analyze the FEM of spatial bars.The results of analysis show that the prestress loss of no stressing end is much more than stressing end while the prestressed tensioning method changed into single-ended from both ends,and the loss will increase with the increase in span,the calculation bending moment of mid-span on no stressing end decrease,and the stress on mid-span plate decrease,therefore,if the prestressed tensioning method changed into single-ended,we should compute and analyze to define the specific impact,then ensure enough buffer for safety.

关 键 词：预应力混凝土箱梁 单端张拉 预应力损失 

分 类 号：U448.21[建筑科学—桥梁与隧道工程]